Lumped Parameter Dynamic Model of an Eversion Growing Robot: Analysis, Simulation and Experimental Validation

This paper presents a lumped-parameter dynamic model of a pressure driven eversion robot carrying a catheter through its hollow core. A simulation framework based on the model is developed in MATLAB and is used for under- standing the underlying physics, for identifying the regions of operation, and for demonstrating that, for a range of input commands, the catheter can be used as an actuation mechanism for propelling eversion; an approach especially useful for miniaturised systems. Simulations are experimentally validated on the MAMMOBOT system, which is a miniature steerable soft growing robot for early breast cancer detection. It was demonstrated that for most regions of operation experimental results compare well with simulation exhibiting an error less than 4%. Only one region of operation demonstrated larger deviations due possibly to unmodeled dynamics, which will be investigated in future work.